Method of forming servo data of HDD and self servo write method using the same

Abstract

A method of forming servo data, and a self-servo write method using the same, the method including partial response maximum likelihood (PRML)-coding servo data into m bits in n-bit units; multiplying each bit of the PRML-coded result by an o multiple; and converting a bitsream obtained in the multiplying to ((m/n)−p) bits in m/n-bit units.

1. A servo data forming method comprising: partial response maximum likelihood (PRML)-coding servo data into m bits in n-bit units; multiplying each bit of the PRML-coded result by an o multiple; and converting a bitstream obtained in the multiplying to ((m/n)−p) bits in m/n−bit units, wherein p is a multiple used for converting the bitstream. 
   
   
     2. The method of  claim 1 , wherein p is less than o. 
   
   
     3. The method of  claim 2 , wherein o is 2, and p is 1. 
   
   
     4. A self-servo write method comprising: partial response maximum likelihood (PRML)-coding servo data into m bits in n-bit units; multiplying each bit of the PRML-coded servo data by an o multiple; down-multiplying by a p multiple, a bitstream obtained in the multiplying to ((m/n)−p) bits in m/n−bit units; and writing the bitstream obtained in the down-multiplying by synchronizing with a clock signal having a frequency f used to write the bitstream obtained in the multiplying. 
   
   
     5. The method of  claim 4 , further comprising:
 generating a clock signal having a frequency of (m/n)/((m/n)−p)*f; and 
 writing the bitstream obtained in the multiplying by synchronizing with the clock signal having the frequency of (m/n)/((m/n)−p)*f. 
 
   
   
     6. The method of  claim 4 , wherein p is less than o. 
   
   
     7. The method of  claim 6 , wherein o is 2, and p is 1. 
   
   
     8. A computer readable medium storing instructions that control at least one processor to perform a method of forming servo data, the method comprising: partial response maximum likelihood (PRML)-coding servo data into m bits in n-bit units; multiplying each bit of the PRML-coded result by an o multiple; and converting a bitstream obtained in the multiplying to ((m/n)−p) bits in m/n−bit units, wherein p is a multiple used for converting the bitstream. 
   
   
     9. The method of  claim 8 , wherein p is less than o. 
   
   
     10. The method of  claim 9 , wherein o is 2, and p is 1. 
   
   
     11. A method of forming servo data, the method comprising: converting a bitstream of partial response maximum likelihood (PRML)-coded servo data, in which each bit has been repeated by a predetermined multiple, into a reduced bitstream of m/n-p bits in m/n-bit units; wherein p is a multiple used for converting the bitstream into the reduced bitstream; and wherein the PRML-coded servo data comprises m bits in n-bit units. 
   
   
     12. The method of  claim 11 , wherein p is less than the predetermined multiple. 
   
   
     13. The method of  claim 12 , wherein the predetermined multiple is 2, and p is 1. 
   
   
     14. A self-servo write method comprising: converting a bitstream of partial response maximum likelihood (PRML)-coded servo data, in which each bit has been repeated by a predetermined multiple, into a reduced bitstream of m/n−p bits in m/n bit units; wherein p is a multiple used for converting the bitstream into the reduced bitstream; and writing the reduced bitstream by synchronizing with a clock signal having a frequency f used to write the servo data; wherein the PRML-coded servo data comprises m bits in n-bit units. 
   
   
     15. The method of  claim 14 , further comprising:
 generating a clock signal having a frequency of (m/n)/((m/n)−p)*f; and 
 writing the reduced bitstream by synchronizing with the clock signal having the frequency of (m/n)/((m/n)−p)*f. 
 
   
   
     16. The method of  claim 14 , wherein p is less than the predetermined multiple. 
   
   
     17. The method of  claim 16 , wherein the predetermined multiple is 2, and p is 1. 
   
   
     18. A method of forming servo data, the method comprising:
 converting a bitstream of partial response maximum likelihood (PRML)-coded servo data, in which each bit has been repeated by a predetermined multiple, into a reduced bitstream; 
 wherein the reduced bitstream comprises units of bits that are each at least one bit shorter than units of bits of the bitstream of PRML-coded servo data.